Nigerian children displaced by the Boko Haram insurgence share a meal at a registration centre in Geidam stadium, Nigeria, file. REUTERS/Afolabi Sotunde

LONDON (Thomson Reuters Foundation) - The number of children suffering from life-threatening malnutrition across the Lake Chad Basin - about 800,000 - has soared since last year, and could spiral further as Boko Haram ramps up attacks in the region, an aid agency said on Tuesday.

The jihadists’ brutal eight-year insurgency has forced millions of people to flee their homes, driven farmers from their land and disrupted aid delivery, leading to a “devastating food crisis”, according to the Norwegian Refugee Council (NRC).

More than 7.2 million people across Nigeria, Cameroon, Niger and Chad need food aid, while the number of children aged under five suffering from severe malnutrition in the region has risen by two-thirds since last September, United Nations data shows.

Yet the reality could be more bleak as a deadly resurgence by Boko Haram this year has left many areas cut off from help and hindered the delivery of humanitarian aid, said Jackie Okao, protection and advocacy adviser at the NRC in Nigeria.

“We are worried that we aren’t aware of all the humanitarian needs, as many areas can’t be accessed by aid groups due to the insecurity,” Okao told the Thomson Reuters Foundation by phone.

“So we don’t know the true number of malnourished children, but it is likely to rise further,” she added. “Without an immediate response, tens of thousands of children may soon die.”

Boko Haram’s bid to create an Islamic state has killed about 20,000 people and forced more than 2.7 million to flee their homes across the Lake Chad region.

A regional offensive last year wrested back large swathes of territory from the Islamist insurgents. But the militants have struck back with renewed zeal recently, targeting civilians and camps sheltering the displaced with raids and suicide bombings.

Boko Haram has killed 381 civilians in Nigeria and Cameroon since the beginning of April, double the number for the preceding five months, mainly by strapping bombs to girls and women, said rights group Amnesty International.

Yet a lack of aid funding has restricted the provision of aid to those people most in need, according to the NRC.

“A lack of sufficient humanitarian funding is putting young children’s lives at risk,” NRC secretary general Jan Egeland said in a statement.

The four countries’ aid response plans for 2017 have been 57 percent funded to date - $1.27 billion of a requested $2.24 billion - according to the U.N.’s Financial Tracking Service.